Fonoster MCP Server

/** * Copyright (C) 2025 by Fonoster Inc (https://fonoster.com) * http://github.com/fonoster/fonoster * * This file is part of Fonoster * * Licensed under the MIT License (the "License"); * you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * https://opensource.org/licenses/MIT * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import { Stream } from "stream"; import { SayOptions, VoiceClientConfig, VoiceIn } from "@fonoster/common"; import { getLogger } from "@fonoster/logger"; import { Bridge, Client } from "ari-client"; import { pickPort } from "pick-port"; import { SpeechResult } from "../stt/types"; import { SpeechToText, TextToSpeech, VoiceClient } from "../types"; import { AudioSocketHandler } from "./AudioSocketHandler"; import { AuthorizationHandler } from "./AuthorizationHandler"; import { ExternalMediaHandler } from "./ExternalMediaHandler"; import { GrpcClientHandler } from "./GrpcClientHandler"; import { SpeechHandler } from "./SpeechHandler"; const logger = getLogger({ service: "apiserver", filePath: __filename }); class VoiceClientImpl implements VoiceClient { config: VoiceClientConfig; verbsStream: Stream; transcriptionsStream: Stream; ari: Client; bridge: Bridge; // Component handlers private authHandler: AuthorizationHandler; private audioSocketHandler: AudioSocketHandler; private externalMediaHandler: ExternalMediaHandler; private grpcHandler: GrpcClientHandler; private speechHandler: SpeechHandler; // Store the speech services for initialization private _tts: TextToSpeech; private _stt: SpeechToText; constructor(params: { ari: Client; config: VoiceClientConfig; tts: TextToSpeech; stt: SpeechToText; }) { const { config, tts, stt, ari } = params; this.config = config; this.ari = ari; this._tts = tts; this._stt = stt; this.verbsStream = new Stream(); this.transcriptionsStream = new Stream(); // Initialize component handlers this.authHandler = new AuthorizationHandler({ config: this.config, ari: this.ari }); this.audioSocketHandler = new AudioSocketHandler({ transcriptionsStream: this.transcriptionsStream, config: this.config }); this.externalMediaHandler = new ExternalMediaHandler({ ari: this.ari, config: this.config }); this.grpcHandler = new GrpcClientHandler({ config: this.config, verbsStream: this.verbsStream }); } async connect() { // Check authorization const isAuthorized = await this.authHandler.checkAuthorization(); if (!isAuthorized) { return; } // Set up GRPC client await this.grpcHandler.setupGrpcClient(); // Set up audio socket and external media const externalMediaPort = await pickPort({ type: "tcp" }); logger.verbose("picked external media port", { port: externalMediaPort }); // Wait for both audio socket and external media setup to complete await Promise.all([ this.audioSocketHandler.setupAudioSocket(externalMediaPort), this.externalMediaHandler.setupExternalMedia(externalMediaPort) ]); // Get the bridge from the external media handler this.bridge = this.externalMediaHandler.getBridge(); // Initialize speech handler now that we have the audio stream this.speechHandler = new SpeechHandler({ tts: this._tts, stt: this._stt, ari: this.ari, transcriptionsStream: this.transcriptionsStream, audioStream: this.audioSocketHandler.getAudioStream(), sessionRef: this.config.sessionRef }); logger.verbose("voice client setup completed"); } // Public API methods required by VoiceClient interface sendResponse(response: VoiceIn): void { this.grpcHandler.sendResponse(response); } on(type: string, callback: (data: VoiceIn) => void): void { this.verbsStream.on(type.toString(), (data: VoiceIn) => { callback(data[type]); }); } async synthesize(text: string, options: SayOptions): Promise<string> { return this.speechHandler.synthesize(text, options); } async stopSynthesis(): Promise<void> { return this.speechHandler.stopSynthesis(); } async transcribe(): Promise<SpeechResult> { return this.speechHandler.transcribe(); } startSpeechGather( callback: (stream: { speech: string; responseTime: number }) => void ): void { this.speechHandler.startSpeechGather(callback); } async startDtmfGather( sessionRef: string, callback: (event: { digit: string }) => void ): Promise<void> { return this.speechHandler.startDtmfGather(callback); } async waitForDtmf(params: { sessionRef: string; finishOnKey: string; maxDigits: number; timeout: number; onDigitReceived: () => void; }): Promise<{ digits: string }> { const { finishOnKey, maxDigits, timeout, onDigitReceived } = params; return this.speechHandler.waitForDtmf({ finishOnKey, maxDigits, timeout, onDigitReceived }); } stopStreamGather(): void { this.speechHandler.stopStreamGather(); } getTranscriptionsStream(): Stream { return this.transcriptionsStream; } close(): void { this.grpcHandler.close(); this.audioSocketHandler.close(); } get tts(): TextToSpeech { return this._tts; } get stt(): SpeechToText { return this._stt; } } export { VoiceClientImpl };